I use zyrtec and it works great for me. Some people do get drowsy on it and they usually suggest you start off taking it at night as a result. But I never experienced that. I've not used Astelin but know a lot of people who do and who like it.
I use both of them and really like them. Some people get dryness from the Astelin. You can use a saline nosepray in between, if that is a problem for you.